Certain 4-oxo-3-benzoylvalerothiolactones

ABSTRACT

Compounds having the formula ##STR1## wherein X is sulfur; 
     R is halogen; C 1  -C 2  alkyl; C 1  -C 2  alkoxy; nitro; cyano; C 1  -C 2  haloalkyl; or R a  SO n  -- wherein n is 0 or 2 and R a  is C 1  -C 2  alkyl; 
     R 1  is hydrogen or C 1  -C 4  alkyl; 
     R 2  is hydrogen or C 1  -C 4  alkyl; 
     R 3  is hydrogen or C 1  -C 4  alkyl; 
     R 4  is hydrogen or C 1  -C 4  alkyl; or 
     R 3  and R 4  together form a single bond; or 
     R 1  and R 3  together are alkylene having 2-5 carbon atoms; or 
     R 2  and R 4  together are alkylene having 2-5 carbon atoms; and 
     R 5  and R 6  independently are (1) hydrogen; (2) halogen; (3) C 1  -C 4  alkyl; (4) C 1  -C 4  alkoxy; (5) trifluoromethoxy; (6) cyano; (7) nitro; (8) C 1  -C 4  haloalkyl; (9) R b  SO n  -- wherein n is the integer 0, 1 or 2; and R b  is (a) C 1  -C 4  alkyl; (b) C 1  -C 4  alkyl substituted with halogen or cyano; (c) phenyl; or (d) benzyl; (10)--NR c  R d  wherein R c  and R d  independently are hydrogen or C 1  -C 4  alkyl; (11) R e  C(O)-- wherein R e  is C 1  -C 4  alkyl or C 1  -C 4  alkoxy; or (12) --SO 2  NR c  R d  wherein R c  and R d  are as defined; and (13) --N(R c )C(O)R d  wherein R c  and R d  are as defined and their salts are useful as herbicides.

This is a divisional of application Ser. No. 871,975, filed June 9,1986.

BACKGROUND OF THE INVENTION

The compound having the structural formula ##STR2## wherein the nitrosubstituent is in the 3- or 4-position are described in J. HeterocyclicChem., 6(1), pp. 13-22 (1969). No utility for these compounds is taught.

Compounds of the structural formula ##STR3## wherein X is halogen, CF₃,alkyl, nitro, cyano or alkoxy are described in European PatentApplication Publication No. 40 082 (1981). The compounds areintermediates for the preparation of certain substituted oxonicotinates.

DESCRIPTION OF THE INVENTION

This invention relates to certain 4-oxo-3-benzoylvalerolacetones andthiolacetones and their salts and their use as herbicides.

One embodiment of this invention is an herbicidal composition comprisingan herbicidally active 4-oxo-3-benzoylvalerolactone or thiolactone andan inert carrier therefor wherein the 2-position of the benzoyl moietyis substituted with halogen; C₁ -C₂ alkyl, preferably methyl; C₁ -C₂alkoxy, preferably methoxy; nitro; cyano; C₁ -C₂ haloaalkyl, preferablytrifluoromethyl or R^(a) SO_(n) -- wherein R^(a) is C₁ -C₂ alkyl,preferably methyl and n is the integer 0 or 2, preferably 2; and the4-position preferably is substituted with an electron withdrawing group,such as halogen, cyano or trifluoromethyl. The 5- and 6-positions of the4-oxo-valerolactone or thiolactone moiety can be substituted, preferablywith the groups hereinafter recited. The 3-, 4-, 5- and 6-positions ofthe benzoyl moiety can be substituted, preferably with the groupshereinafter recited.

Also embodied within the scope of this invention are novel compoundshaving the following structural formula ##STR4## wherein X is oxygen orsulfur;

R is halogen, C₁ -C₂ alkyl, preferably methyl; C₁ -C₂ alkoxy, preferablymethoxy; nitro; cyano; C₁ -C₂ haloalkyl, preferably trifluoromethyl; orR^(a) SO_(n) -- wherein R^(a) is C₁ -C₂ alkyl, preferably methyl and nis the integer 0 or 2, preferably 2;

R¹ is hydrogen or C₁ -C₄ alkyl, preferably C₁ -C₂ alkyl, more preferablymethyl, most preferably R¹ is hydrogen or methyl;

R² is hydrogen; C₁ -C₄ alkyl, preferably C₁ -C₂ alkyl, more preferablymethyl most preferably R² is hydrogen or methyl; or

R³ is hydrogen or C₁ -C₄ alkyl, preferably C₁ -C₂ alkyl, more preferablymethyl; most preferably R³ is hydrogen or methyl;

R⁴ is hydrogen or C₁ -C₄ alkyl, preferably C₁ -C₂ alkyl, more preferablymethyl; most preferably R⁴ is hydrogen or methyl; or

R³ and R⁴ together form a single bond; or

R¹ and R² together are alkylene having 2-5 carbon atoms; or

R² and R⁴ together are alkylene having 2-5 carbon atoms;

R⁵ and R⁶ independently are (1) hydrogen; (2) halogen, preferablychlorine, fluorine or bromine; (3) C₁ -C₄ alkyl, preferably methyl; (4)C₁ -C₄ alkoxy, preferably methoxy; (5) trifluoromethoxy; (6) cyano; (7)nitro; (8) C₁ -C₄ haloalkyl, more preferably trifluoromethyl; (9) R^(b)SO_(n) -- wherein n is the integer 0, 1 or 2, preferably 2; and

R^(b) is

(a) C₁ -C₄ alkyl, preferably methyl;

(b) C₁ -C₄ alkyl substituted with halogen or cyano, preferablychloromethyl, trifluoromethyl or cyanomethyl;

(c) phenyl; or

(d) benzyl;

(10) --NR^(c) R^(d) wherein R^(c) and R^(d) independently are hydrogenor C₁ -C₄ alkyl;

(11) R^(e) C(O)-- wherein R^(e) is C₁ -C₄ alkyl or C₁ -C₄ alkoxy;

(12) --SO₂ NR^(c) R^(d) wherein R^(c) and R^(d) are as defined; and

(13) --N(R^(C))C(O)R^(d) wherein R^(c) and R^(d) are as defined.

The term "C₁ -C₄ alkyl" includes methyl, ethyl, n-propyl, isobutyl,n-butyl, sec-butyl, isobutyl and t-butyl. The term "halogen" includeschlorine, bromine, iodine and fluorine. The term "C₁ -C₄ alkoxy"includes methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy,isobutoxy and t-butoxy. The term "C₁ -C₄ haloalkyl" includes the alkylgroups defined above under C₁ -C₄ alkyl in which one or more hydrogensare replaced by chlorine, bromine, iodine or fluorine.

Preferably, R⁵ is in the 3-position. Most preferably R⁵ is hydrogen orC₁ -C₄ alkoxy. Preferably R⁶ is in the 4-position. More preferably, R⁶is hydrogen, chlorine, cyano, fluorine, trifluoromethyl, or R^(b) SO₂wherein R^(b) is C₁ -C₄ alkyl, preferably methyl or C₁ -C₄ haloalkyl,preferably chloromethyl, difluoromethyl or trifluoromethyl.

Salts of the above-described compounds (as defined hereinafter) areincluded within the scope of the subject of the instant invention.

The compounds of this invention can have the following three structuralformulae because of tautomerism: ##STR5## wherein X, R, R¹, R², R³, R⁴,R⁵ and R⁶ are as defined above.

The circled proton on each of the three tautomers is reasonably labile.These protons are acidic and can be removed by reaction with a base toform a salt having an anion of the following three resonance forms:##STR6## wherein X, R, R¹, R², R³, R⁴, R⁵ and R⁶ are as defined above.

Examples of cations of these bases are inorganic cations such as alkalimetals, e.g. lithium, sodium and potassium; the alkaline earth metals,e.g. calcium and magnesium or ammonium or organic cations such assubstituted ammonium, sulfonium,, sulfoxonium or phosphonium wherein thesubstituents are aliphatic or aromatic groups.

Those skilled in the art will recognize in considering the salts of thisinvention that varying degrees of association between the anion andcation will exist depending upon the nature of the cation. In someinstances with a suitable cation, such as copper, the salt can exist ina chelated form.

The compounds of this invention and their salts are active herbicides ofa general type. That is, they are herbicidally effective against a widerange of plant species. The method of controlling undesirable vegetationof the present invention comprises applying an herbicidally effectiveamount of the above described compounds to the area where control isdesired.

The compounds of the present invention can be prepared by the followingtwo-step general method.

The process proceeds via the production of an enol ester intermediate asshown in reaction (1). The final product is obtained by rearrangement ofthe enol ester as shown in reaction (2). The two reactions may beconducted as separate steps by isolation and recovery of the enol esterusing conventional techniques prior to conducting step (2), or byaddition of a cyanide source to the reaction medium after the formationof the enol ester, or in one step by inclusion of the cyanide source atthe start of reaction (1). ##STR7## wherein X and R through R⁶ are asdefined and Y is halogen, preferably chlorine, C₁ -C₄ alkyl-C(O)--O--,C₁ -C₄ alkoxy-C(O)--O-- or ##STR8## wherein R, R⁵ and R⁶ in this portionof the molecule are identical with those in the reactant shown above andthe moderate base is as defined, preferably tri-C₁ -C₆ alkylamine,alkali metal carbonate or alkali metal phosphate.

Generally, in step (1) mole amounts of the lactone or thiolactone andsubstituted benzoyl reactant are used, along with a mole amount orexcess of the base. The two reactants are combined in an organic solventsuch as methylene chloride, toluene, ethyl acetate or dimethylformamide.The base or benzoyl reactant preferably is added to the reaction mixturewith cooling. The mixture is stirred at 0° C.-50° C. until the reactionis substantially complete.

The reaction product is worked up by conventional techniques. ##STR9##wherein X and R through R⁶ are as defined.

Generally, in step (2) a mole of the enol ester intermediate is reactedwith 1 to 4 moles of the moderate base, preferably about 2 moles ofmoderate base and from 0.01 mole to about 0.5 mole or higher, preferablyabout 0.1 mole of the cyanide source (e.g., potassium cyanide or acetonecyanohydrin). The mixture is stirred in a reaction pot until therearrangement is substantially complete at a temperature below 80° C.,preferably about 20° C. to about 40° C., and the desired product isrecovered by conventional techniques.

The term "cyanide source" refers to a substance or substances whichunder the rearrangement conditions consists of or generates hydrogencyanide and/or cyanide anion.

The process is conducted in the presence of a catalytic amount of asource of cyanide anion and/or hydrogen cyanide, together with a molarexcess, with respect to the enol ester, of a moderate base.

Preferred cyanide sources are alkali metal cyanides such as sodium andpotassium cyanide; cyanohydrins of methyl alkyl ketones having from 1-4carbon atoms in the alkyl groups, such as acetone or methyl isobutylketone cyanohydrins; cyanohydrins of benzaldehyde or of C₂ -C₅ aliphaticaldehydes such as acetaldehyde, propionaldehyde, etc., cyanohydrins;zinc cyanide; tri(lower alkyl) silyl cyanides, notably trimethyl silylcyanide; and hydrogen cyanide itself. Hydrogen cyanide is consideredmost advantageous as it produces relatively rapid reaction and isinexpensive. Among cyanohydrins the preferred cyanide source is acetonecyanohydrin.

The cyanide source is used in an amount up to about 50 mole percentbased on the enol ester. It may be used in as little as about 1 molepercent to produce an acceptable rate of reaction at about 40° C. on asmall scale. Larger scale reactions give more reproducible results withslightly higher catalyst levels of about 2 mole percent. Generally about1-10 mole % of the cyanide source is preferred.

The process is conducted with a molar excess, with respect to the enolester, of a moderate base. By the term "moderate base" is meant asubstance which acts as a base yet whose strength or activity as a baselies between that of strong bases such as hydroxides (which could causehydrolysis of the enol ester) and that of weak bases such asbicarbonates (which would not function effectively). Moderate basessuitable for use in this embodiment include both organic bases such astertiary amines and inorganic bases such as alkali metal carbonates andphosphates. Suitable tertiary amines include trialkylamines such astriethylamine. Suitable inorganic bases include potassium carbonate andtrisodium phosphate.

The base is used in an amount of from about 1 to about 4 moles per moleof enol ester, preferably about 2 moles per mole.

When the cyanide source is an alkali metal cyanide, particularlypotassium cyanide, a phase transfer catalyst may be included in thereaction. Particularly suitable phase transfer catalysts are the Crownethers.

A number of different solvents are useful in this process, depending onthe nature of the acid chloride or the acylated product. A preferredsolvent for this reaction is acetonitrile. Other solvents which can beemployed, depending on the reactants or products include toluene,1,2-dichloroethane, methylene chloride, ethyl acetate,dimethylformamide, and methyl isobutyl ketone (MIBK).

In general, depending on the nature of the reactants and the cyanidesource, the rearrangement may be conducted at temperatures up to about50° C.

The above described substituted benzoyl chlorides can be prepared fromthe corresponding substituted benzoic acids according to the teaching ofReagents for Organic Synthesis, Vol. I, L. F. Fieser and M. Fieser, pp.767-769 (1967). ##STR10## wherein R, R⁵ and R⁶ are as previouslydefined.

The substituted benzoic acids can be prepared by a wide variety ofgeneral methods according to the teaching of The Chemistry of CarboxylicAcids and Esters, S. Patai, editor, J. Wiley and Sons, New York, N.Y.(1969) and Survey of Organic Synthesis, C. A. Buehler and D. F. Pearson,J. Wiley and Sons, (1970).

The following are four representative examples of the methods describedtherein. ##STR11## wherein R, R⁵ and R⁶ are as previously defined.

In reaction (a) the substituted benzonitrile is heated to reflux inaqueous sulfuric acid for several hours. The mixture is cooled and thereaction product is isolated by conventional techniques. ##STR12##wherein R, R⁵ and R⁶ are as previously defined.

In reaaction (b) the substituted acetophenone is heated to reflux forseveral hours in an aqueous hypochlorite solution. The mixture is cooledand the reaction product is isolated by conventional techniques.##STR13## wherein R, R⁵ and R⁶ are as defined and X is chlorine, bromineor iodine.

The substituted aromatic halide is allowed to react with magnesium in asolvent such as ether. The solution is then poured over crushed dry iceand the benzoic acid is isolated by conventional techniques.

The above-described valerolactones or valerothiolactones can be preparedaccording to the teaching of K. Schweiger, Monatshefte fur Chemie, 113,1283 (1982); N. Bellara et al., J. Het. Chem., 15, 1153 (1978); and H.Meyer and D. Seebach, Liebig's Ann. Chem., 2261 (1975).

The following example teaches the synthesis of a representative compoundof this invention.

EXAMPLE 1 3-(2'-Nitrobenzoyl)-6-methyl-4-oxovalerolactone ##STR14##

6-Methyl-4-oxovalerolactone (2.6 g, 20 mmol) and 2-nitrobenzoylchloride(3.8 g, 20 mmol) were dissolved in 30 ml methylene chloride and stirredat room temperature. Triethylamine (2.2 g, 20 mmol) in 20 ml methylenechloride was added dropwise, and the resulting mixture was stirred for 2hours. The reaction mixture was then poured into 1N HCl and extractedwith additional methylene chloride. The organic layer was then washedwith 5% K₂ CO₃, brine, then dried with MgSO₄ and evaporated to yield anoil (4.2 g, 76%) which was used without further purification.

Two and sixty-seven one-hundredths grams (10 mmol) of the prepared enolester was dissolved in 50 ml acetonitrile and stirred at roomtemperature. Triethylamine (2.0 g, 20 mmol) and acetone cyanohydrin (0.1g, 1 mmol) were added all at once, and the resulting mixture stirred for5 hours. The solvent was evaporated and the resulting oil dissolved inether. The organic liquid was then washed with 1N HCl, brine, dried withMgSO₄ and evaporated to yield an oil which crystallized on standing (2.3g, 86%, m.p. 84°-89° C.) which was identified as the desired compound bynuclear magnetic resonance spectroscopy, infrared spectroscopy and massspectroscopy.

The following is a table of certain selected compounds that arepreparable according to the procedure described hereto. Compound numbersare assigned to each compound and are used throughout the remainder ofthe application.

                                      TABLE I                                     __________________________________________________________________________     ##STR15##                                                                    Comp.                                                                         No. R  R.sup.1                                                                          R.sup.2                                                                          R.sup.3                                                                         R.sup.4                                                                          R.sup.5                                                                           R.sup.6                                                                             X m.p. °C.                                 __________________________________________________________________________     1  Cl H  CH.sub.3                                                                         bond H   4-Cl  O    126-128° C.                            2  Cl H  CH.sub.3                                                                         H H  H   4-Cl  O oil                                              3  NO.sub.2                                                                         H  CH.sub.3                                                                         H H  H   4-Cl  O oil                                               4.sup.(a)                                                                       NO.sub.2                                                                         H  CH.sub.3                                                                         H H  H   H     O 84-89                                            5  Cl H  CH.sub.3                                                                         H H  H   4-SO.sub.2 CH.sub.3                                                                 O oil                                              6  CH.sub.3                                                                         H  CH.sub. 3                                                                        H H  H   4-Br  O 93-96                                            7  CH.sub.3                                                                         H  CH.sub.3                                                                         bond H   H     O brown semi-solid                                 8  Cl H  CH.sub.3                                                                         bond H   4-Cl  O  94-102                                          9  Br H  CH.sub.3                                                                         bond H   H     O oil                                             10  Cl H  CH.sub.3                                                                         bond 3-NO.sub.2                                                                        H     O oil                                             11  CH.sub.3                                                                         H  CH.sub.3                                                                         bond H   4-Br  O 106-110                                         12  Cl H  CH.sub.3                                                                         H CH.sub.3                                                                         H   4-NO.sub.2                                                                          O 92-96                                           13  Cl CH.sub.3                                                                         CH.sub.3                                                                         H CH.sub.3                                                                         H   4-NO.sub.2                                                                          O 72-76                                           14  Cl H  *  H *  H   4-SO.sub.2 CH.sub.3                                                                 O 102-105                                         15  Cl H  CH.sub.3                                                                         H CH.sub.3                                                                         H   4-SO.sub.2 CH.sub.3                                                                 O 122-126                                         16  Cl CH.sub.3                                                                         CH.sub.3                                                                         H CH.sub.3                                                                         H   4-SO.sub.2 CH.sub.3                                                                 O oil                                             17  Cl CH.sub.3                                                                         CH.sub.3                                                                         H CH.sub.3                                                                         H   4-Cl  O 145-149                                         18  Cl H  *  H *  H   4-NO.sub.2                                                                          O oil                                             19  NO.sub.2                                                                         H  CH.sub.3                                                                         H CH.sub.3                                                                         H   4-Cl  O oil                                             20  NO.sub.2                                                                         H  CH.sub.3                                                                         H CH.sub.3                                                                         H   4-Cl  S --                                              21  Cl H  CH.sub.3                                                                         H CH.sub.3                                                                         H   4-SO.sub.2 CH.sub.3                                                                 S 166-170                                         22  Cl H  CH.sub.3                                                                         H CH.sub.3                                                                         H   4-Cl  S 142-143                                         __________________________________________________________________________     .sup.(a) Prepared in Example 1.                                               * = CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2-                                 

Herbicidal Screening Tests

As previously mentioned, the herein described compounds produced in theabove-described manner are phytotoxic compounds which are useful andvaluable in controlling various plant species. Selected compounds ofthis invention were tested as herbicides in the following manner.

Pre-emergence herbicide test. On the day preceding treatment, seeds ofseven different weed species are planted in loamy sand soil inindividual rows using one species per row across the width of a flat.The weeds used are green foxtail (FT) (Setaria viridis), watergrass (WG)(Echniochloa crusgalli), wild oat (WO) (Avena fatua), annualmorningglory (AMG) (Ipomoea lacunosa), velvetleaf (VL) (Abutilontheophrasti), Indian mustard (MD) (Brassica juncea) and yellow nutsedge(YNG) (Cyperus esculentus). Ample seeds are planted to give about 20 to40 seedlings per row, after emergence, depending upon the size of theplants.

Using an analytical balance, 600 milligrams (mg) of the compound to betested are weighed out on a piece of glassine weighing paper. The paperand compound are placed in a 60 milliliter (ml) wide-mouth clear bottleand dissolved in 45 ml of acetone or substituted solvent. Eighteen ml ofthis solution are transferred to a 60 ml wide-mouth clear bottle anddiluted with 22 ml of a water and acetone mixture (19:1) containingenough polyoxyethylene sorbitan monolaurate emulsifier to give a finalsolution of 0.5% (v/v). The solution is then sprayed on a seeded flat ona linear spray table calibrated to deliver 80 gallons per acre (748L/ha). The application rate is 4 lb/acre (4.48 Kg/ha).

After treatment, the flats are placed in the greenhouse at a temperatureof 70° to 80° F. and watered by sprinkling. Two weeks after treatment,the degree of injury or control is determined by comparison withuntreated check plants of the same age. The injury rating from 0 to 100%is recorded for each species as percent control with 0% representing noinjury and 100% representing complete control.

The results of the tests are shown in the following Table II.

                  TABLE II                                                        ______________________________________                                        Pre-Emergence Herbicidal Activity                                             Application Rate - 4.48 kg/ha                                                 Cmpd.                                                                         No.    FT     WG      WO   AMG   VL    MD   YNG                               ______________________________________                                        1      95     70      45   10    100   100  50                                2      95     90      10   75    100   95   95                                3      100    100     80   90    100   100  80                                4      100    100     70   95    100   100  80                                5      100    100     5    100   100   100  80                                6      100    100     10   90    100   100  80                                7      0      0       0    0     0     0    0                                 8      100    10      100  100   100   100  80                                9      100    10      70   20    95    95   0                                 10     20     0       0    10    10    60   0                                 11     100    60      60   40    100   100  80                                12     20     50      0    60    100   100  0                                 13     20     100     0    10    90    100  70                                14     0      30      0    50    100   100  80                                15     80     95      20   50    95    100  80                                16     100    100     50   60    85    100  80                                17     80     80      0    0     85    90   80                                18     0      40      0    5     80    80   20                                19     100    100     90   95    100   100  80                                20     80     95      0    100   100   100  80                                21     80     100     0    100   100   100  80                                22     30     80      0    100   100   100  80                                ______________________________________                                    

Post-Emergence Herbicide Test: This test is conducted in an identicalmanner to the testing procedure for the pre-emergence herbicide test,except the seeds of the seven different weed species are planted 10-12days before treatment. Also, watering of the treated flats is confinedto the soil surface and not to the foliage of the sprouted plants.

The results of the post-emergence herbicide test are reported in TableIII.

                  TABLE III                                                       ______________________________________                                        Post-Emergence Herbicidal Activity                                            Application Rate - 4.48 kg/ha                                                 Cmpd.                                                                         No.    FT     WG      WO   AMG   VL    MD   YNG                               ______________________________________                                        1      95     55      40   70    100   100  65                                2      75     75      10   75    100   65   75                                3      70     80      80   50    80    95   80                                4      100    100     85   50    90    90   70                                5      100    95      80   80    100   100  30                                6      75     40      0    100   100   100  30                                7      10     0       10   60    90    10   0                                 8      85     30      85   100   100   65   80                                9      50     10      0    10    90    100  0                                 10     0      0       0    30    80    80   0                                 11     60     40      30   100   100   100  60                                12     10     30      0    20    60    90   30                                13     0      60      0    20    50    50   0                                 14     0      60      0    20    50    50   30                                15     10     70      20   80    90    100  70                                16     50     50      50   80    50    50   30                                17     30     50      0    60    80    80   33                                18     0      0       0    5     5     5    0                                 19     95     100     80   100   100   100  80                                20     0      30      0    40    80    80   30                                21     0      50      0    90    90    100  50                                22     0      50      0    80    90    100  50                                ______________________________________                                    

The compounds of the present invention and their salts are useful asherbicides and can be applied in a variety of ways at variousconcentrations. In practice, the compounds or salts are formulated intoherbicidal compositions, by admixture, in herbicidally effectiveamounts, with the adjuvants and carriers normally employed forfacilitating the dispersion of active ingredients for agriculturalapplications, recognizing the fact that the formulation and mode ofapplication of a toxicant may affect the activity of the materials in agiven application. Thus, these active herbicidal compounds or salts canbe formulated as granules of relatively large particle size, as wettablepowders, as emulsifiable concentrates, as powdery dusts, as flowables,as solutions or as any of several other known types of formulations,depending upon the desired mode of application. These formulations maycontain as little as about 0.5% to as much as about 95% or more byweight of active ingredient. A herbicidally effective amount dependsupon the nature of the seeds or plants to be controlled and the rate ofapplication varies from about 0.01 to approximately 10 pounds per acre,preferably from about 0.02 to about 4 pounds per acre.

Wettable powders are in the form of finely divided particles whichdisperse readily in water or other dispersants. The wettable powder isultimately applied to the soil either as a dry dust or as a dispersionin water or other liquid. Typical carriers for wettable powders includefuller's earth, kaolin clays, silicas and other readily wet organic orinorganic diluents. Wettable powders normally are prepared to containabout 5% to about 95% of the active ingredient and usually also containa small amount of wetting, dispersing, or emulsifying agent tofacilitate wetting and dispersion.

Emulsifiable concentrates are homogeneous liquid compositions which aredispersible in water or other dispersant, and may consist entirely ofthe active compound or salt with a liquid or solid emulsifying agent, ormay also contain a liquid carrier, such as xylene, heavy aromaticnaphthal, isophorone and other non-volatile organic solvents. Forherbicidal application, these concentrates are dispersed in water orother liquid carrier and normally applied as a spray to the area to betreated. The percentage by weight of the essential active ingredient mayvary according to the manner in which the composition is to be applied,but in general comprises about 0.5% to 95% of active ingredient byweight of the herbicidal composition.

Granular formulations wherein the toxicant is carried on relativelycoarse particles, are usually applied without dilution to the area inwhich suppression of vegetation is desired. Typical carriers forgranular formulations include sand, fuller's earth, attapulgite clay,bentonite clays, montmorillonite clay, vermiculite, perlite and otherorganic or inorganic materials which absorb or which may be coated withthe toxicant. Granular formulations normally are prepared to containabout 5% to about 25% of active ingredients which may includesurface-active agents such heavy aromatic naphthas, kerosene or otherpetroleum fractions, or vegetable oils; and/or stickers such asdestrins, glue or synthetic resins.

Typical wetting, dispersing or emulsifying agents used in agriculturalformulations include, for example, the alkyl and alkylaryl sulfonatesand sulfates and their salts; polyhydric alcohols; polyethoxylatedalcohols; esters and fatty amines; and other types of surface-activeagents, many of which are available in commerce. The surface-activeagent, when used, normally comprises from 0.1% to 15% by weight of theherbicidal composition.

Dusts, which are free-flowing admixtures of the active ingredient withfinely divided solids such as talc, clays, flours and other organic andinorganic solids which act as dispersants and carriers for the toxicant,are useful formulations for soil-incorporating application.

Pastes, which are homogeneous suspensions of a finely divided solidtoxicant in a liquid carrier such as water or oil, are employed forspecific purposes. These formulations normally contain about 5% to about95% of active ingredient by weight, and may also contain small amountsof a wetting, dispersing or emulsifying agent to facilitate dispersion.For application, the pastes are normally diluted and applied as a sprayto the area to be affected.

Other useful formulations for herbicidal applications include simplesolutions of the active ingredient in a dispersant in which it iscompletely soluble at the desired concentration, such as acetone,alkylated naphthalenes, xylene and other organic solvents. Pressurizedsprays, typically aerosols, wherein the active ingredient is dispersedin finely-divided form as a result of vaporization of a low boilingdispersant solvent carrier, such as the Freons, may also be used.

The phytotoxic compositions of this invention can be applied to theplants in the conventional manner. Thus, the dust and liquidcompositions can be applied to the plant by the use of power-dusters,boom and hand sprayers and spray dusters. The compositions can also beapplied from airplanes as a dust or a spray or by rope wick applicationsbecause they are effective in very low dosages. In order to modify orcontrol growth of germinating seeds or emerging seedlings, as a typicalexample, the dust and liquid compositions can be applied to the soilaccording to conventional methods and can be distributed in the soil toa depth of at least 1/2 inch below the soil surface. It is not necessarythat the phytotoxic compositions be mechanically admixed with the soilparticles since these compositions can also be applied merely byspraying or sprinkling the surface of the soil. The phytotoxiccompositions of this invention can also be applied by addition toirrigation water supplied to the field to be treated. This method ofapplication permits the penetration of the compositions into the soil asthe water is absorbed therein. Dust compositions, granular compositionsor liquid formulations applied to the surface of the soil can bedistributed below the surface of the soil by conventional means such asdiscing, dragging or mixing operations. In the following examples theherbicidal compound can be substituted with the herbicidal salt of thecompound.

    __________________________________________________________________________    General Formula with Ranges                                                                     Specific Formula                                            __________________________________________________________________________    EMULSIFIABLE CONCENTRATE FORMULATIONS                                         Herbicidal compound                                                                       5-55  herbicidal compound                                                                         24                                            surfactant(s)                                                                             5-25  proprietary blend of oil-                                                                   10                                            solvent(s)  20-90 soluble sulfonates and                                                  100%  polyoxyethylene ethers                                                        polar solvent 27                                                              petroleum hydrocarbon                                                                       39                                                                             100%                                         WETTABLE POWDER FORMULATIONS                                                  herbicidal compound                                                                       3-90  herbicidal compound                                                                         80                                            wetting agent                                                                             0.5-2 sodium dialkyl naphthalene                                                                  0.5                                           dispersing agent                                                                          1-8   sulfonate                                                   diluent(s)  8.5-87                                                                              sodium lignosulfonate                                                                       7                                                         100%  attapulgite clay                                                                            12.5                                                                           100%                                         EXTRUDED GRANULAR FORMULATIONS                                                herbicidal compound                                                                       1-20  herbicidal compound                                                                         10                                            binding agent                                                                             0-10  lignin sulfonate                                                                             5                                            diluent(s)  70-99 calcium carbonate                                                                           85                                                        100%                 100%                                         FLOWABLE FORMULATIONS                                                         herbicidal compound                                                                       20-70 herbicidal compound                                                                         45                                            surfactant(s)                                                                             1-10  polyoxyethylene ether                                                                       5                                             suspending agent(s)                                                                       0.05-1                                                                              attagel       0.05                                          antifreeze agent                                                                          1-10  propylene glycol                                                                            10                                            antimicrobial agent                                                                       1-10  1,2-benzisothiazoline-3-one                                                                 0.03                                          antifoam agent                                                                            0.1-1 silicone defoamer                                                                           0.02                                          solvent     7.95-77.85                                                                          water         39.9                                                      100%                 100%                                         __________________________________________________________________________

When salts are used as the active ingredient in the herbicidalcompositions of this invention it is recommended to use salts that areagriculturally acceptable.

The phytotoxic compositions of this invention can also contain otheradditives, for example, fertilizers, other herbicides and otherpesticides, used as adjuvant or in combination with any of theabove-described adjuvants. Fertilizers useful in combination with theactive ingredients include, for example, ammonium nitrate, urea andsuperphosphate.

What is claimed is:
 1. Compounds of the formula ##STR16## wherein X is sulfur;R is halogen; C₁ -C₂ alkyl; C₁ -C₂ alkoxy; nitro; cyano; C₁ -C₂ haloalkyl; or R^(a) SO_(n) -- wherein n is 0 or 2 and R^(a) is C₁ -C₂ alkyl; R¹ is hydrogen or C₁ -C₄ alkyl; R² is hydrogen or C₁ -C₄ alkyl; R³ is hydrogen or C₁ -C₄ alkyl; R⁴ is hydrogen or C₁ -C₄ alkyl; or R¹ and R³ together are alkylene having 2-5 carbon atoms; or R² and R⁴ together are alkylene having 2-5 carbon atoms; and R⁵ and R⁶ independently are (1) hydrogen; (2) halogen; (3) C₁ -C₄ alkyl; (4) C₁ -C₄ alkoxy; (5) trifluoromethoxy; (6) cyano; (7) nitro; (8) C₁ -C₄ haloalkyl; (9) R^(b) SO_(n) -- wherein n is the integer 0, 1 or 2; and R^(b) is (a) C₁ -C₄ alkyl; (b) C₁ -C₄ alkyl substituted with halogen or cyano; (c) phenyl; or (d) benzyl; (10) --NR^(c) R^(d) independently are hydrogen or C₁ -C₄ alkyl; (11) R^(e) C(O)-- wherein R^(e) is C₁ -C₄ alkyl or C₁ -C₄ alkoxy; or (12) --SO₂ NR^(c) R^(d) wherein R^(c) and R^(d) are as defined; and (13) --N(R^(c))C(O)R^(d) wherein R^(c) and R^(d) are as defined and their salts.
 2. The compound of claim 1 wherein X is sulfur, R is chlorine, R¹ is hydrogen, R² is methyl, R³ is hydrogen, R⁴ is methyl, R⁵ is hydrogen and R⁶ is 4-SO₂ CH₃.
 3. An herbicidal composition comprising an herbicidally active 3-(benzoyl)-4-oxovalerothiolactone compound of the formula ##STR17## wherein X is sulfur;R is halogen; C₁ -C₂ alkyl; C₁ -C₂ alkoxy; nitro; cyano; C₁ -C₂ haloalkyl; or R^(a) SO_(n) -- wherein n is 0 or 2 and R^(a) is C₁ -C₂ alkyl; R¹ is hydrogen or C₁ -C₄ alkyl; R² is hydrogen or C₁ -C₄ alkyl; R³ is hydrogen or C₁ -C₄ alkyl; R⁴ is hydrogen or C₁ -C₄ alkyl; or R³ and R⁴ together form a single bond; or R¹ and R³ together are alkylene having 2-5 carbon atoms; or R² and R⁴ together are alkylene having 2-5 carbon atoms; and R⁵ and R⁶ independently are (1) hydrogen; (2) halogen; (3) C₁ -C₄ alkyl; (4) C₁ -C₄ alkoxy; (5) trifluoromethoxy; (6) cyano; (7) nitro; (8) C₁ -C₄ haloalkyl; (9) R^(b) SO_(n) -- wherein n is the integer 0, 1 or 2; and R^(b) is (a) C₁ -C₄ alkyl; (b) C₁ -C₄ alkyl substituted with halogen or cyano; (c) phenyl; or (d) benzyl; (10) --NR^(c) R^(d) wherein R^(c) and R^(d) independently are hydrogen or C₁ -C₄ alkyl; (11) R^(e) C(O)-- wherein R^(e) is C₁ -C₄ alkyl or C₁ -C₄ alkoxy; or (12) --SO₂ NR^(c) R^(d) wherein R^(c) and R^(d) are as defined; and (13) --N(R^(c))C(O)R.sup. d wherein R^(c) and R^(d) are as defined and their salts and an inert carrier therefor.
 4. The composition of claim 3 wherein X is sulfur; R is chlorine, bromine, C₁ -C₂ alkyl, C₁ -C₂ alkoxy, cyano, nitro, C₁ -C₂ alkylthio or C₁ -C₂ alkylsulfonyl; R¹ is hydrogen or methyl; R² is hydrogen or methyl; R³ is hydrogen or methyl; R⁴ is hydrogen or methyl; R⁵ and R⁶ independently are (1) hydrogen; (2) halogen; (3) C₁ -C₄ alkyl; (4) C₁ -C₄ alkoxy; (5) trifluoromethoxy; (6) cyano; (7) nitro; (8) C₁ -C₄ haloalkyl; (9) R^(b) SO_(n) -- wherein n is the integer 0, 1 or 2; and R^(b) is (a) C₁ -C₄ alkyl; (b) C₁ -C₄ alkyl substituted with halogen or cyano; (c) phenyl; or (d) benzyl; (10) --NR^(c) R^(d) wherein R^(c) and R^(d) independently are hydrogen or C₁ -C₄ alkyl; (11) R^(e) C(O)-- wherein R^(e) is C₁ -C₄ alkyl or C₁ -C₄ alkoxy; (12) SO₂ NR^(c) R^(d) wherein R^(c) and R^(d) are as defined; or (13) --N--(R^(c) C(O)R^(d) wherein R^(c) and R^(d) are as defined.
 5. The composition of claim 3 wherein X is sulfur, R is chlorine, R¹ is hydrogen, R² is methyl, R³ is hydrogen, R⁴ is methyl, R⁵ is hydrogen and R⁶ is 4-SO₂ CH₃. 